barack obama. some have signed a petition on whitehouse.gov to say he shouldn't perform. >> the president is supposed to attend that. we'll see. thank you. >>> john travolta and olivia newton john go back to their "grease" roots and pot smokers rejoice. it all happened in five chaotic days. we'll catch you up on the week that was, but first if your cell phone or other tech devices need recharging, new technology makes you the energy generator. cnn's gary tuchman explains in this week's "start small, think big." >> my name is aaron lemieux. i'm founder and ceo of tremont electric and the inven earth of the n power peg >> reporter: designed for hikers, bikers or anyone on the go. >> as you walk along it harvests and stores your human kinetic energy and recharges your mobile electronic devices from the energy that it harvests from you. >> peg stands for personal energy generator. >> demonstrate it simply by standing here and walking in place. >> reporter: aaron lemieux dreamed up the ideas as an engin